5661001 has 2 divisors, whose sum is σ = 5661002. Its totient is φ = 5661000.

The previous prime is 5660999. The next prime is 5661041. The reversal of 5661001 is 1001665.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5645376 + 15625 = 2376^2 + 125^2 .

It is a cyclic number.

It is not a de Polignac number, because 5661001 - 2¹ = 5660999 is a prime.

Together with 5660999, it forms a pair of twin primes.

5661001 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 5661001.

It is not a weakly prime, because it can be changed into another prime (5661041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2830500 + 2830501.

It is an arithmetic number, because the mean of its divisors is an integer number (2830501).

Almost surely, 2^5661001 is an apocalyptic number.

It is an amenable number.

5661001 is a deficient number, since it is larger than the sum of its proper divisors (1).

5661001 is an equidigital number, since it uses as much as digits as its factorization.

5661001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 5661001 is about 2379.2858172149. The cubic root of 5661001 is about 178.2232711460.

Adding to 5661001 its reverse (1001665), we get a palindrome (6662666).

The spelling of 5661001 in words is "five million, six hundred sixty-one thousand, one".